Cardiac support devices are structures, sometimes referred to as jackets, that surround all or portions of a diseased heart. These devices are intended to treat chronic heart failure or other cardiac disease, which may be associated valvular dysfunction, by constraining expansion of the heart. They can be delivered and implanted using conventional cardiothoracic surgical techniques or minimally invasive surgical procedures. Devices of these types and associated delivery tools and methods are shown, for example, in the following U.S. patents and published applications, all of which are incorporated herein by reference in their entirety.
Inventor NamePatent/Publication No.Alferness5,702,343Alferness et al.6,123,662Vanden Hoek et al.6,293,906Alferness et al.6,482,146Lau et al.6,702,732Cox et al.6,730,016Walsh et al.6,902,522Girard et al.6,951,534Walsh et al.2007/0208215Pignato et al.2007/0270654
Cardiac support devices (CSDs) can be implanted via conventional median sternotomy surgical procedures. In the course of an implantation using this procedure, the heart is typically lifted and the CSD is placed over the ventricles. It is then sutured along its base end to the epicardial fat near the atrioventricular (A-V) groove of the heart to prevent migration. Minimally invasive procedures can also be used to implant CSDs. CSDs configured for minimally invasive implantation can have elastomeric structures such as elastic bands incorporated into the base end of the CSD. The elastotmeric band can attach the CSD to the heart (e.g., adjacent to the A-V groove).
CSDs have also been implanted using limited access techniques through a left minithoracotomy with fluoroscopic visualization. These techniques are attractive because they avoid median sternotomy, involve substantially less musculoskeletal trauma and can be performed with minimal heart manipulation. They are therefore associated with less hemodynamic stress.
Unfortunately, limited access approaches may not permit direct intraoperative visualization of the CSD. Fluoroscopic visualization can demonstrate the general shape of the heart and the location of the heart apex, but may not effectively show the location of other structures such as the A-V groove, the coronary sinus, the atrial appendages or the location of the pulmonary artery or right ventricular outflow tract. Although structures of the CSD may be radioopaque, and visible through fluoroscopic imaging, the locations of these CSD structures with respect to those of the heart can be difficult to assess. Accurate placement of the CSD can therefore be difficult to assess. There remains, therefore, a need for improved methods and structures for implanting CSDs. In particular, there is a need for improved methods and structures for accurately placing CSDs on the patients' hearts.